A metamaterial, radome and aircraft

Abstract

This invention provides a metamaterial comprising a substrate material layer and a metal sheet layer superimposed on the substrate material layer. The metal sheet layer has periodic slots in a single direction. The substrate material layer and the metal sheet layer together form a single unit, and a terminal is connected to one end in a single direction, which is then connected to an external power source to form a conductive path for electric heating using the property of metal to conduct electricity. Furthermore, this invention also provides a radome and an aircraft. The technical solution provided by this invention employs a specific structural design for the metal sheet layer, enabling it to function both as an electric heating unit with electric heating de-icing capabilities and as an electromagnetic modulation structure, allowing electromagnetic signal transmission within the operating frequency range of electromagnetic transceivers while shielding electromagnetic waves outside the operating frequency range and suppressing interference from clutter signals.

Description

Technical Field

[0001] This invention relates to the field of materials, and more specifically, to a metamaterial, a radome, and an aircraft. Background Technology

[0002] Icing is a widespread physical phenomenon affecting aircraft during flight and is a major hidden danger to flight safety. When an aircraft flies in sub-icing weather conditions, supercooled water droplets in the atmosphere impact the aircraft's surface and easily sublimate and form ice on prominent parts of the fuselage, such as the leading edges of wings, rotors, tail rotors, engine air intakes, pitot tubes, windshields, and radomes. Icing not only increases the weight of the aircraft but also disrupts its aerodynamic shape, alters the flow field, and impairs aerodynamic performance, resulting in reduced maximum lift, increased drag, and decreased flight performance. In severe cases, it can pose a fatal threat to flight safety. Furthermore, for military aircraft such as drones and transport aircraft, icing directly restricts their flight area and significantly impacts their combat capabilities. Therefore, de-icing protection must be implemented for critical components prone to icing.

[0003] Existing de-icing methods mainly include: hot gas de-icing, mechanical de-icing, microwave de-icing, and electrothermal de-icing. However, hot gas de-icing, which uses engine bleed air, requires the design of complex air supply pipelines to distribute the hot gas drawn from the engine compressor to the parts that need de-icing, and it also affects the engine's power and operating efficiency. Mechanical de-icing, which uses airbags and expansion tubes to break up the ice layer, will damage the aircraft's aerodynamic shape and is not thorough in de-icing. Microwave de-icing is easily detected by radar. In addition, traditional electrothermal de-icing generally uses metal foil, metal wire, conductive metal film, resistance wire, etc. as electric heating units, which are not suitable for components that require electromagnetic transmission functions.

[0004] Therefore, how to achieve both de-icing and electromagnetic modulation functions on aircraft to ensure the transmission of electromagnetic signals has become a pressing issue that the industry urgently needs to address. Summary of the Invention

[0005] To address the above problems, the present invention provides a metamaterial, wherein the metamaterial includes a substrate material layer and a metal sheet layer superimposed on the substrate material layer. The metal sheet layer has periodic slits in a single direction. The substrate material layer and the metal sheet layer together form a whole, and the end of the whole in a single direction is connected to a terminal, which is connected to an external power source to form a conductive path for electric heating by utilizing the electric heating characteristic of metal.

[0006] Preferably, the metamaterial further includes a first prepreg layer, which is bonded to the metal sheet layer by an adhesive.

[0007] Preferably, the metamaterial further includes a second prepreg layer, which is bonded to the substrate material layer by an adhesive.

[0008] Preferably, the metamaterial further includes a core layer, which is bonded to the second prepreg layer by an adhesive film.

[0009] Preferably, the metamaterial further includes a third prepreg layer, which is bonded to the core layer by an adhesive film.

[0010] Preferably, the gaps extend through the entire metal sheet layer, the multiple gaps are parallel to each other, and each gap is a straight line.

[0011] Preferably, the gaps extend through the entire metal sheet layer, the multiple gaps are parallel to each other, each gap includes multiple V-shaped gaps connected in sequence, and the opening angle of the V-shaped gaps is greater than 0 degrees and less than or equal to 180 degrees.

[0012] Preferably, the gaps extend through the entire metal sheet layer, the multiple gaps are parallel to each other, and each gap includes multiple sinusoidal wave gaps connected in sequence.

[0013] In addition, the present invention also provides a de-icing device, wherein the de-icing device comprises the metamaterial described in any of the above claims.

[0014] In addition, the present invention also provides a radome, wherein the radome comprises the metamaterial described in any of the above claims.

[0015] Furthermore, the present invention also provides an aircraft comprising the metamaterial described in any of the preceding claims.

[0016] The technical solution provided by this invention solves the problem that existing electrothermal de-icing methods cannot achieve electromagnetic signal transmission due to the shielding of electromagnetic signals by the metal layer. By designing a conductive metal path and a specific design for the metal path, it can suppress interference from external electromagnetic signals outside the operating frequency band of the internal electromagnetic transceiver devices. This makes it possible to place electromagnetic transceiver devices, such as microwave and millimeter-wave antennas, in locations with good electromagnetic transmission visibility. This lays the foundation for the development of aircraft towards multi-sensor integration and all-space perception, and further enhances the full information chain connectivity of high-end aviation equipment. Attached Figure Description

[0017] Figure 1 This is a cross-sectional schematic diagram of a multi-layered structure included in the metamaterial in the first embodiment of the present invention;

[0018] Figure 2This is a cross-sectional schematic diagram of another multi-layered structure included in the metamaterial in the second embodiment of the present invention;

[0019] Figure 3 This is a two-dimensional cross-sectional schematic diagram of another multi-layered metamaterial included in the second embodiment of the present invention;

[0020] Figure 4 This is a schematic diagram of the structure of the metal sheet 2 included in the metamaterial of the second embodiment of the present invention, which has periodic gaps in the horizontal direction.

[0021] Figure 5 This is a schematic diagram showing the change of the S21 curve of the metamaterial under TE polarization with the incident angle theta in the second embodiment of the present invention.

[0022] Figure 6 This is a schematic diagram showing the change of the S21 curve of the metamaterial under TM polarization with the incident angle theta in the second embodiment of the present invention.

[0023] Figure 7 This is a schematic diagram of the structure of the metamaterial comprising the metal sheet 2 with periodic slots opened in the vertical direction in the second embodiment of the present invention;

[0024] Figure 8 As in the second embodiment of the present invention Figure 7 A schematic diagram showing the variation of the S21 curve of a metamaterial under TE polarization with the incident angle theta.

[0025] Figure 9 As in the second embodiment of the present invention Figure 7 A schematic diagram showing the variation of the S21 curve of a metamaterial under TM polarization with the incident angle theta.

[0026] Figure 10 This is a schematic diagram of the first type of V-shaped slit structure on the metal sheet 2 included in the metamaterial in the second embodiment of the present invention;

[0027] Figure 11 As in the second embodiment of the present invention Figure 10 A schematic diagram showing the variation of the S21 curve of a metamaterial under TE polarization with the incident angle theta.

[0028] Figure 12 As in the second embodiment of the present invention Figure 10 A schematic diagram showing the variation of the S21 curve of a metamaterial under TM polarization with the incident angle theta.

[0029] Figure 13 This is a schematic diagram of the second type of V-shaped slit structure on the metal sheet 2 included in the metamaterial in the second embodiment of the present invention;

[0030] Figure 14 As in the second embodiment of the present invention Figure 13 A schematic diagram showing the change of the S21 curve of the metamaterial under TE polarization at the incident angle theta = 0°;

[0031] Figure 15 As in the second embodiment of the present invention Figure 13 A schematic diagram showing the change of the S21 curve of the metamaterial under TM polarization at the incident angle theta = 0°;

[0032] Figure 16 This is a schematic diagram of the third V-shaped slit structure on the metal sheet 2 included in the metamaterial in the second embodiment of the present invention;

[0033] Figure 17 As in the second embodiment of the present invention Figure 16 A schematic diagram showing the change of the S21 curve of the metamaterial under TE polarization at the incident angle theta = 0°;

[0034] Figure 18 As in the second embodiment of the present invention Figure 16 A schematic diagram showing the change of the S21 curve of the metamaterial under TM polarization at the incident angle theta = 0°;

[0035] Figure 19 This is a schematic diagram of the sinusoidal wave slit structure on the metal sheet layer 2 included in the metamaterial in the second embodiment of the present invention;

[0036] Figure 20 As in the second embodiment of the present invention Figure 19 A schematic diagram showing the change of the S21 curve of the metamaterial under TE polarization at the incident angle theta = 0°;

[0037] Figure 21 As in the second embodiment of the present invention Figure 19 A schematic diagram showing the change of the S21 curve of the metamaterial under TM polarization at the incident angle theta = 0°. Detailed Implementation

[0038] The following embodiments are intended to enable those skilled in the art to more fully understand the present invention, but do not limit the invention in any way.

[0039] Figure 1 This is a cross-sectional schematic diagram of the multi-layered structure included in the metamaterial in the embodiment of the present invention.

[0040] like Figure 1As shown, the metamaterial of this invention adopts a multi-layered structure design. Specifically, the metamaterial includes a substrate material layer 1 and a metal sheet layer 2 superimposed on the substrate material layer 1. The metal sheet layer 2 has periodic slots in the horizontal direction, forming a horizontally conductive metal connection structure. The substrate material layer 1 and the metal sheet layer 2 together form a whole, and the horizontal ends of the whole are connected to terminals 3, which are connected to an external power source through two terminals 3 to form a conductive path. The characteristic of metal heating by electricity can be used to electrically heat parts prone to freezing. The substrate material layer 1 can be either a flexible substrate material layer or a rigid substrate material layer, depending on the actual application scenario. For example, if the metamaterial is applied to a curved surface, a flexible substrate material layer is required; if applied to a plane, either a rigid or flexible substrate material layer can be selected. The base material layer 1 has excellent insulation properties, resistance to high and low temperatures, and good mechanical properties such as tensile strength. The base material layer 1 and the metal sheet layer 2 together form a whole called a flexible metal board. The flexible metal board is connected to a terminal 3 at its horizontal end. The terminal 3 can be connected to the metal on the metal sheet layer 2 by welding or other connection methods, as long as the terminal 3 and the metal on the metal sheet layer 2 are electrically connected. The two terminals 3 are respectively connected to the positive and negative poles of an external power supply through a power line, so that a conductive path structure is formed between the metal on the metal sheet layer 2, the two terminals 3, the power line, and the external power supply. The external power supply uses the characteristic of the metal sheet layer 2 to conduct electric heating through this electrical path structure.

[0041] like Figure 1 As shown, in a flexible metal board, the metal (i.e., metal sheet 2) on the substrate material layer 1 is etched using an etching process, so that periodic slots are formed on a complete metal sheet in the horizontal direction. The slots penetrate the entire metal sheet, and multiple slots are parallel to each other, with each slot being a straight line; or the slots penetrate the entire metal sheet, and multiple slots are parallel to each other, with each slot including multiple sequentially connected V-shaped slots, the opening angle of the V-shaped slots being greater than 0 degrees and less than or equal to 180 degrees; or the slots penetrate the entire metal sheet, and multiple slots are parallel to each other, with each slot including multiple sequentially connected sinusoidal wave slots.

[0042] On the substrate material layer 1, the areas of the metal sheet layer 2 that have not been etched away retain the metal. The metal retained in the metal sheet layer 2 forms a horizontally conductive interconnect structure, which is a horizontally interconnect structure with periodic arrangement.

[0043] like Figure 1As shown, the metamaterial also includes a first prepreg layer 4 and a second prepreg layer 5, which are bonded to the front and back surfaces of the flexible metal sheet by two layers of adhesive 6. Specifically, the first prepreg layer 4 is bonded to the front surface of the metal sheet layer 2 by one layer of adhesive 6, and the back surface of the metal sheet layer 2 is superimposed on the front surface of the substrate material layer 1. The second prepreg layer 5 is bonded to the back surface of the substrate material layer 1 by another layer of adhesive 6. The prepreg in both the first and second prepreg layers 4 and 5 is a fiber prepreg such as glass or quartz, which serves to provide insulation and strength support. The two layers of adhesive 6 are used to better bond the first and second prepreg layers 4 and 5 to the front and back surfaces of the flexible metal sheet.

[0044] In this embodiment, the metal sheet layer 2 has a periodically arranged horizontally conductive metal interconnect structure. This periodically arranged horizontally interconnect structure is fabricated by etching the metal on the substrate material layer 1 in a flexible metal substrate, resulting in periodic slots in the horizontal direction on a complete metal sheet. Specifically, this interconnected metal structure pattern can be considered a unidirectional slotted metal structure pattern. From an external physical perspective, the unidirectional slotted metal structure pattern can be seen as slotted units formed by etching away some metal units in a certain arrangement on the surface of a complete metal layer. Electrons generated by this slotted metal structure pattern can flow unrestricted under electromagnetic wave irradiation. From a frequency response perspective, the slotted metal structure pattern possesses electromagnetic modulation effects of single-polarization wide cutoff, orthogonal polarization low-pass, and fast cutoff. Specifically, the mechanism of this electromagnetic modulation effect is manifested in:

[0045] a) When a low-frequency electromagnetic wave with an electric field direction parallel to the unidirectional slot irradiates the surface of this slotted metal structure, it excites a large number of electrons to move freely along the direction of the metal sheet. This causes the electrons to absorb most of the energy, while the induced current around the slot is very small. The electromagnetic wave transmission capability is weak, resulting in a very low transmission coefficient and strong cutoff. Furthermore, because the metal sheet is very wide, electrons can move freely on the metal sheet over a wide frequency range, thus exhibiting a very wideband cutoff characteristic.

[0046] (b) When electromagnetic waves irradiate the unidirectional slit with an electric field perpendicular to it, the long period of the low-frequency electromagnetic waves and the slow change in the electric field direction mean the unidirectional slit remains in the same charged state for a considerable time, unable to form a radiation loop until the electric field direction changes. Therefore, electrons at the edge of the unidirectional slit absorb only a small portion of the energy, resulting in strong electromagnetic wave transmission. The opposite is true for high-frequency incident waves. Due to the shorter period of high-frequency electromagnetic waves and the faster change in the electric field direction, electrons in the metal oscillate continuously, absorbing most of the energy, weakening the transmission capability, and lowering the transmission coefficient. This exhibits the characteristics of low-frequency transmission and rapid cutoff. Furthermore, because the slit is very narrow, it maintains a stable charged state only at very low frequencies. As the frequency increases, electrons around the slit oscillate rapidly, causing a rapid decrease in transmission capability, exhibiting the characteristics of low-frequency transmission and rapid high-frequency cutoff.

[0047] In this embodiment, the surface of this slotted metal structure pattern can also be freely combined with non-connected annular metal surface micro-elements and patch-type metal surface micro-elements to achieve the required electromagnetic modulation characteristics. This invention combines the electromagnetic response characteristics and structural and strength requirements of electromagnetic transceivers, selects materials for the composite layer containing electric heating and electromagnetic modulation functions, and integrates the design of thickness and metal structure patterns to achieve an integrated component that combines structure, strength, and composite electric heating and electromagnetic modulation functions.

[0048] In this embodiment, depending on requirements such as structural strength and electromagnetic control performance, the metamaterial can be further augmented with new composite dielectric layers, such as... Figure 2 As shown.

[0049] Figure 2 This is a cross-sectional schematic diagram of another multi-layered structure included in the metamaterial in this embodiment of the invention.

[0050] like Figure 2 As shown, the dashed box A represents... Figure 1 In the metamaterial, the dashed box B represents the newly added composite dielectric layer. Figure 1 Based on the metamaterial structure shown, Figure 2 The metamaterial also includes a core layer 87 and a third prepreg layer 98. One side of the core layer 87 is bonded to the second prepreg layer 65 via an adhesive film 109, and the third prepreg layer 98 is bonded to the other side of the core layer 87 via another adhesive film 109. In this embodiment, for the newly added combined dielectric layer, in order to achieve better electromagnetic modulation performance, the present invention can also embed it separately in the core layer 87 or the third prepreg layer 98. Figure 1 The metal flexible plate shown (i.e., the substrate material layer 1 and the metal sheet layer 2 together form a whole) is used as the electromagnetic modulation layer.

[0051] Figure 3This is a two-dimensional cross-sectional schematic diagram of another multi-layered metamaterial included in the second embodiment of the present invention.

[0052] Figure 3 The structural diagram shown is the one that... Figure 2 A two-dimensional cross-sectional diagram of a multi-layered metamaterial formed by pressing together multiple layers together. Figure 3 The metamaterial structure shown is a sandwich structure that integrates de-icing, electromagnetic modulation, and structural load-bearing functions. It consists of nine layers. Specifically, from top to bottom, the thickness of the first prepreg layer 4 is d1, the thickness of the adhesive layer 6 is d2, the thickness of the metal flexible plate (including the base material layer 1 and the metal sheet layer 2) is d3, the thickness of the other adhesive layer 6 is d4, the thickness of the second prepreg layer 5 is d5, the thickness of the adhesive film 9 is d6, the thickness of the core layer 7 is d7, the thickness of the other adhesive film 9 is d8, and the thickness of the third prepreg layer 8 is d9.

[0053] In this invention, the prepregs in the first prepreg layer 4, the second prepreg layer 5, and the third prepreg layer 8 are all low-dielectric, low-loss quartz fiber cyanate prepregs, which have high wave transmission and load-bearing capacity. At the same time, the first prepreg layer 4, the second prepreg layer 5, and the third prepreg layer 8 are all good skin materials. The first prepreg layer 4 and the second prepreg layer 5 can be used as outer skin materials, and the third prepreg layer 8 can be used as inner skin materials. Both adhesive layers 6 can be bonded with adhesive films. The flexible metal board, as an electric heating layer, is mainly composed of heating materials and insulating materials. The metal sheet layer 2 in this invention is the heating material, which is made of copper metal with high resistivity and high conductivity. The base material layer 1 in this invention is the insulating material, which is mainly a polyimide (PI) film with excellent comprehensive performance. The core layer 7, as a honeycomb layer, realizes electromagnetic performance optimization and load-bearing function.

[0054] The thickness of the metal layer 2 is determined based on the required resistance; a thicker metal layer results in lower resistance, while a thinner metal layer produces higher resistance. In this embodiment, the metal layer 2 has a thickness of 18 μm, and the substrate material layer 1 (i.e., the PI film) has a thickness of 25 μm. Therefore, the flexible metal plate composed of these two materials serves as an electric heating layer, making it flexible and easy to apply to curved surfaces. Furthermore, the copper metal can be designed with different topological patterns to achieve frequency-selective electromagnetic modulation. Simultaneously, the metal layer 2 has a connected structure, ensuring that the metal in the metal layer 2 can form a conductive path after being energized, enabling the function of heating and de-icing. To achieve frequency selection with different polarizations and frequency bands, the metal layer 2 also needs to have a periodic arrangement structure and a horizontally connected structure. The layers of this invention are bonded together using an adhesive film. Of the materials used above, the dielectric constant of the skin material is 3.15 and the loss tangent is 0.006; the dielectric constant of the adhesive film material is 2.7 and the loss tangent is 0.0065; the dielectric constant of the PI film material is 3.2 and the loss tangent is 0.002; and the dielectric constant of the honeycomb material is 1.11 and the loss tangent is 0.006.

[0055] Figure 4 This is a schematic diagram of the structure in the second embodiment of the present invention, in which the metal sheet 2 of the metamaterial has periodic slots in the horizontal direction.

[0056] like Figure 4 As shown, the metal sheet layer 2 has a structure with periodic slits in the horizontal direction. In Figure (a) opening method one, the black part represents the metal sheet, and the white part between two adjacent metal sheets represents the slit structure formed by etching away the metal. Specifically, the slits run through the entire metal sheet layer, and multiple slits are parallel to each other, with each slit being a straight line. Figure 4 As shown, the width of the straight slits is ww, and the width of each individual metal sheet on metal sheet layer 2 separated by the slits is p, with a distance of ww between two adjacent metal sheets. Figure (b) shows the second slit method.

[0057] In this embodiment, Figure 4 (a) The periodic arrangement of the structure on the metal sheet 2 shown is applied to Figure 3 The main structural dimensions of the stacked structure shown are illustrated in Table 1 below:

[0058] Table 1 Main Structural Dimensions

[0059]

[0060]

[0061] Then, based on the dimensions in the table above... Figure 3Simulations were performed on metamaterials in the image, and the results are as follows: Figure 5 and Figure 6 As shown.

[0062] from Figure 5 and Figure 6 As can be seen, when the incident angle theta = 0 to 60°, the TE polarization exhibits high transmission characteristics in the ultra-low frequency range of 0-0.4 GHz, with a transmission greater than -1.2 dB. When the frequency is greater than 3 GHz, the transmission is less than -10 dB, exhibiting ultra-wideband cutoff characteristics. When theta = 0 to 60°, the TM polarization exhibits full-band cutoff characteristics in the range of 0-18 GHz, with a transmission less than -70 dB.

[0063] The simulation results show that when phi = 0° (phi represents the angle between the incident electromagnetic wave and the z-axis), the continuous metal sheets along the horizontal direction are equivalent to a broadband cutoff in the TM direction and a frequency-selective high-pass structure with low-pass and fast cutoff in the TE direction, enabling relatively independent modulation of the TM wave. Similarly, by changing the continuous periodic arrangement of the metal sheets along the vertical direction, such as... Figure 7 As shown, the continuous metal sheet along the vertical direction is equivalent to a frequency-selective high-pass structure with wideband cutoff in the TE direction and low-pass and fast cutoff in the TM direction, which can realize relatively independent modulation of the TE wave. The specific dimensions are shown in Table 1.

[0064] Then, based on the dimensions in the table above... Figure 7 Simulations were performed on metamaterials in the image, and the results are as follows: Figure 8 and Figure 9 As shown.

[0065] Figure 8 As in the second embodiment of the present invention Figure 7 A schematic diagram showing the variation of the S21 curve of a metamaterial under TE polarization with the incident angle theta.

[0066] Figure 9 As in the second embodiment of the present invention Figure 7 A schematic diagram showing the variation of the S21 curve of the metamaterial under TM polarization with the incident angle theta.

[0067] from Figure 8 and Figure 9 As can be seen, when the incident angle theta = 0 to 60°, the TE polarization exhibits full-band cutoff characteristics in the 0-20GHz range, with transmission less than -70dB; when theta = 0 to 50°, the TM polarization exhibits high transmission characteristics in the 0-1GHz ultra-low frequency range, with transmission greater than -1.3dB, and the transmission is less than -8dB when the frequency is greater than 3GHz, exhibiting ultra-wideband cutoff characteristics.

[0068] Therefore, from Figure 5 , Figure 6 , Figure 8 and Figure 9 The simulation results show that the metamaterial in this invention achieves electromagnetic modulation function with single-polarization wideband cutoff and low-pass and fast cutoff in another orthogonal polarization direction. This linear horizontally connected structure composed of a single-direction continuous metal sheet can achieve electromagnetic modulation function on the basis of realizing electric heating de-icing, and can realize the above-mentioned electromagnetic modulation function.

[0069] Furthermore, this invention not only features a structure with periodic slits on the metal sheet 2 in a single direction, but also allows each slit to be straight, enabling both electric heating and de-icing functions as well as electromagnetic modulation functions. Other types of slit structures, such as bending straight slit structures (e.g., V-shape) or transforming them into arbitrary polygonal periodic boundaries (e.g., rectangular waveform), can also form a connected structure to achieve a conductive path as long as the bent slit structure penetrates the entire metal sheet in a single direction. This allows for de-icing when the layer is energized as an electric heating layer. Moreover, by designing the main structural dimensions in the stacked structure, it can also be equipped with electromagnetic modulation functions.

[0070] Figure 10 This is a schematic diagram of the first V-shaped slit structure on the metal sheet 2 included in the metamaterial in the second embodiment of the present invention.

[0071] like Figure 10 As shown, the slits penetrate the entire metal sheet layer 2, and the multiple slits are parallel to each other. Each slit includes multiple sequentially connected V-shaped slits. The opening angle of each V-shaped slit is greater than 0 degrees and less than or equal to 180 degrees. In this embodiment, the opening angle of each V-shaped slit is 120 degrees. Figure 10 As shown, the topology consists of slots arranged along two sides of a regular hexagonal metal sheet with a period of P and an included angle of 120°. The slot period is N (N≥2, and N is an integer), and the slot width is ww. Here, N represents the number of regular hexagonal metal sheets with a period of P that are spaced apart from adjacent metal sheets in the Y direction. In this embodiment, the period corresponding to the bent TM slot is 2, meaning that adjacent bent slots are spaced apart by two regular hexagonal metal sheets with a period of P. Therefore, the slots have a different period than the metal sheets and dielectric stack.

[0072] In this embodiment, Figure 10 The periodic arrangement of the metal sheets shown is applied to... Figure 3 The main structural dimensions of the stacked structure shown are illustrated in Table 2 below:

[0073] Table 2 Main Structural Dimensions

[0074]

[0075]

[0076] Then, based on the dimensions in the table above... Figure 3 Simulations were performed on metamaterials in the image, and the results are as follows: Figure 11 and Figure 12 As shown.

[0077] Figure 11 As in the second embodiment of the present invention Figure 10 A schematic diagram showing the variation of the S21 curve of a metamaterial under TE polarization with the incident angle theta.

[0078] Figure 12 As in the second embodiment of the present invention Figure 10 A schematic diagram showing the variation of the S21 curve of the metamaterial under TM polarization with the incident angle theta.

[0079] from Figure 11 and Figure 12 As can be seen, when the incident angle theta = 0 to 60°, the TE polarization exhibits transmission characteristics in the ultra-low frequency range of 0-0.4 GHz, with a transmission greater than -2 dB, and exhibits cutoff characteristics in the high frequency range; when theta = 0 to 60°, the TM polarization exhibits cutoff characteristics across the entire frequency band in the range of 0-14 GHz, with a transmission less than -30 dB in all frequencies.

[0080] Figure 13 This is a schematic diagram of the second type of V-shaped slit structure on the metal sheet layer 2 included in the metamaterial in the second embodiment of the present invention.

[0081] like Figure 13 As shown, the slits penetrate the entire metal sheet layer 2, and the slits are parallel to each other. Each slit includes multiple V-shaped slits connected sequentially. The opening angle of each V-shaped slit is greater than 0 degrees and less than or equal to 180 degrees. In this embodiment, the opening angle of each V-shaped slit is 60 degrees. The side length of each V-shaped slit is a, the slit period is p (p = N * a (N is a positive integer)), and the slit width is ww.

[0082] In this embodiment, Figure 13 The periodic arrangement of the metal sheets shown is applied to... Figure 3 The main structural dimensions of the stacked structure shown are illustrated in Table 3 below:

[0083] Table 3 Main Structural Dimensions

[0084]

[0085]

[0086] Then, based on the dimensions in the table above... Figure 13 Simulations were performed on metamaterials in the image, and the results are as follows: Figure 14 and Figure 15 As shown.

[0087] Figure 14 As in the second embodiment of the present invention Figure 13 A schematic diagram showing the change of the S21 curve of the metamaterial under TE polarization at the incident angle theta = 0°.

[0088] Figure 15 As in the second embodiment of the present invention Figure 13 A schematic diagram showing the change of the S21 curve of the metamaterial under TM polarization at the incident angle theta = 0°.

[0089] from Figure 14 and Figure 15 As can be seen from the data, when the incident angle theta = 0° and N = 2, the TE polarization exhibits transmission characteristics in the ultra-low frequency range of 0-0.7GHz, with a transmission greater than -1dB, and exhibits cutoff characteristics in the high frequency range; the TM polarization exhibits low-frequency cutoff characteristics in the range of 0-16GHz, with a transmission less than -10dB in all frequencies.

[0090] Figure 16 This is a schematic diagram of the third V-shaped slit structure on the metal sheet layer 2 included in the metamaterial in the second embodiment of the present invention.

[0091] like Figure 16 As shown, the slits penetrate the entire metal sheet layer 2, and the slits are parallel to each other. Each slit includes multiple V-shaped slits connected sequentially. The opening angle of each V-shaped slit is greater than 0 degrees and less than or equal to 180 degrees. In this embodiment, the opening angle of each V-shaped slit is 90 degrees. The side length of each V-shaped slit is a, the slit period is p (p = N * a (N is a positive integer)), and the slit width is ww.

[0092] In this embodiment, Figure 16 The periodic arrangement of the metal sheets shown is applied to... Figure 3 The main structural dimensions of the stacked structure shown are illustrated in Table 4 below:

[0093] Table 4 Main Structural Dimensions

[0094]

[0095]

[0096] Then, based on the dimensions in the table above... Figure 16 Simulations were performed on metamaterials in the image, and the results are as follows: Figure 17 and Figure 18 As shown.

[0097] Figure 17 As in the second embodiment of the present invention Figure 16A schematic diagram showing the change of the S21 curve of the metamaterial under TE polarization at the incident angle theta = 0°.

[0098] Figure 18 As in the second embodiment of the present invention Figure 16 A schematic diagram showing the change of the S21 curve of the metamaterial under TM polarization at the incident angle theta = 0°.

[0099] from Figure 17 and Figure 18 As can be seen from the data, when the incident angle theta = 0°, the TE polarization exhibits transmission characteristics in the ultra-low frequency range of 0-1.4GHz, with a transmission greater than -1dB, and exhibits cutoff characteristics in the high frequency range; the TM polarization exhibits low-frequency cutoff characteristics in the range of 0-16GHz, with a transmission less than -10dB in all frequencies.

[0100] In addition, in this invention, not only can the periodic arrangement of straight gaps, V-shaped gaps and other horizontally connected structures achieve the functions of electric heating de-icing and electromagnetic modulation, but the periodic arrangement of curved single-direction connected structures can also achieve the functions of electric heating de-icing and electromagnetic modulation.

[0101] Figure 19 This is a schematic diagram of the sinusoidal wave slit structure on the metal sheet layer 2 included in the metamaterial in the second embodiment of the present invention.

[0102] like Figure 19 As shown, the gaps penetrate the entire metal sheet layer 2, and the gaps are parallel to each other. Each gap includes multiple sinusoidal wave gaps connected in sequence. The period of the sinusoidal wave curve is a, the gap period is p (p = N * a (N is a positive integer)), and the gap width is ww.

[0103] In this embodiment, Figure 19 The periodic arrangement of the metal sheets shown is applied to... Figure 3 The main structural dimensions of the stacked structure shown are illustrated in Table 5 below:

[0104] Table 5 Main Structural Dimensions

[0105]

[0106]

[0107] Then, based on the dimensions in the table above... Figure 19 Simulations were performed on metamaterials in the image, and the results are as follows: Figure 20 and Figure 21 As shown.

[0108] Figure 20 As in the second embodiment of the present invention Figure 19A schematic diagram showing the change of the S21 curve of the metamaterial under TE polarization at the incident angle theta = 0°.

[0109] Figure 21 As in the second embodiment of the present invention Figure 19 A schematic diagram showing the change of the S21 curve of the metamaterial under TM polarization at the incident angle theta = 0°.

[0110] from Figure 20 and Figure 21 As can be seen from the data, when the incident angle theta = 0°, the TE polarization exhibits transmission characteristics in the ultra-low frequency range of 0-1.3GHz, with a transmission greater than -1dB, and exhibits cutoff characteristics in the high frequency range; the TM polarization exhibits low-frequency cutoff characteristics in the range of 0-20GHz, with a transmission less than -18dB in all frequencies.

[0111] Therefore, the periodic arrangement of the curved, single-direction connected structure in this invention can also realize the functions of electric heating and de-icing as well as electromagnetic modulation. As long as the arrangement is continuous in a single direction, a conductive path can be formed, which can then serve as an electric heating layer to realize the de-icing function when energized. Moreover, by designing the main structural dimensions in the stacked structure, it can also have the function of electromagnetic modulation.

[0112] Therefore, it can be seen that the linear and curved unidirectional connected structures in this invention can achieve the function of electric heating de-icing under periodic arrangement. Moreover, as long as the unidirectional continuous arrangement is met, a conductive path can be formed, thereby achieving the de-icing function when the electric heating layer is energized. Furthermore, by designing the main structural dimensions in the stacked structure, it can also have electromagnetic modulation function. In addition to ensuring that the metal layer is a connected structure, the electric heating layer (i.e., the flexible metal board) that achieves the de-icing function also needs to connect the metal on the electric heating layer to the power line through solder joints to form a terminal. The terminal is connected to the airborne power supply on the aircraft via the power line. The heat generated by the electric heating layer melts a thin layer between the ice layer and the outer skin, reducing the adhesion between the ice layer and the outer skin. In this way, the ice layer can be easily blown off under the action of aerodynamic force or centrifugal force.

[0113] In addition, the present invention also provides a de-icing device, wherein the de-icing device comprises the metamaterial described in any of the above claims.

[0114] In addition, the present invention also provides a radome, wherein the radome comprises the metamaterial described in any of the above claims.

[0115] Furthermore, the present invention also provides an aircraft comprising the metamaterial described in any of the preceding claims.

[0116] The technical solution provided by this invention combines electromagnetic modulation function with de-icing function. By designing a conductive metal path and specific design of the metal path, it solves the problem that existing de-icing methods cannot guarantee electromagnetic signal transmission due to the shielding of electromagnetic signals by the metal layer. At the same time, it can suppress interference from external electromagnetic signals outside the operating frequency band of the electromagnetic transceiver devices inside the component. This makes it possible to place electromagnetic transceiver devices, such as microwave and millimeter-wave antennas, in locations with good electromagnetic transmission field of view. It also lays the foundation for the development of aircraft towards multi-sensor integration and all-space perception, which will further enhance the full information chain connectivity of high-end aviation equipment.

[0117] Those skilled in the art should understand that the above embodiments are merely exemplary embodiments, and various changes, substitutions, and modifications can be made without departing from the spirit and scope of the present invention.

Claims

1. A metamaterial, characterized in that, The metamaterial includes a substrate material layer and a metal sheet layer superimposed on the substrate material layer. The metal sheet layer has periodic slits in a single direction. The substrate material layer and the metal sheet layer together form a whole. The end of the whole in a single direction is connected to a terminal and connected to an external power source through the terminal to form a conductive path for electric heating by utilizing the electric heating characteristic of metal. The metal sheet layer has periodically arranged horizontally or vertically oriented conductive interconnections. These periodically arranged horizontally or vertically oriented interconnections are fabricated by etching the metal on the substrate material layer in a flexible metal substrate, creating periodic slots in the horizontal or vertical directions on a complete metal sheet. Specifically, this interconnected metal structure pattern is defined as a unidirectional slot-type metal structure pattern. From a frequency response perspective, the unidirectional slot-type metal structure pattern possesses electromagnetic modulation capabilities with low-frequency transmission and rapid high-frequency cutoff. Specifically, when the electric field... When electromagnetic waves are irradiated perpendicular to a one-way slit, the one-way slit remains in the same charged state for a long time due to the long period of low-frequency electromagnetic waves and the slow change of the electric field direction. It cannot form a radiation loop until the electric field direction changes. Therefore, the electrons at the edge of the one-way slit absorb only a small portion of the energy, resulting in strong electromagnetic wave transmission capability and exhibiting low-frequency wave transmission characteristics. The situation is exactly the opposite for high-frequency incident waves. Due to the short period of high-frequency electromagnetic waves and the rapid change of the electric field direction, the electrons in the metal oscillate continuously, absorbing most of the energy. The transmission capability weakens, the transmission coefficient decreases, and it exhibits high-frequency rapid cutoff characteristics. The unidirectional slits penetrate the entire metal sheet layer, and multiple unidirectional slits are parallel to each other. Each unidirectional slit includes multiple V-shaped slits connected sequentially, and the opening angle of the V-shaped slits is greater than 0 degrees and less than or equal to 180 degrees. When the incident angle theta = 0 to 60°, the metamaterial under TE polarization exhibits wave transmission characteristics at ultra-low frequencies of 0-0.4 GHz with a wave transmission greater than -2 dB, and exhibits cutoff characteristics at high frequencies. When the incident angle theta = 0 to 60°, the metamaterial under TM polarization exhibits full-band cutoff characteristics at 0-14 GHz with a wave transmission less than -30 dB.

2. The metamaterial according to claim 1, characterized in that, The metamaterial also includes a first prepreg layer, which is bonded to the metal sheet layer by an adhesive.

3. The metamaterial according to claim 2, characterized in that, The metamaterial also includes a second prepreg layer, which is bonded to the substrate material layer by an adhesive.

4. The metamaterial according to claim 3, characterized in that, The metamaterial also includes a core layer, which is bonded to the second prepreg layer by an adhesive film.

5. The metamaterial according to claim 4, characterized in that, The metamaterial also includes a third prepreg layer, which is bonded to the core layer by an adhesive film.

6. A de-icing device, characterized in that, The de-icing device comprises the metamaterial described in any one of claims 1-5.

7. A radar dome, characterized in that, The radome comprises the metamaterial described in any one of claims 1-5.

8. An aircraft, characterized in that, The aircraft comprises the metamaterial described in any one of claims 1-5.

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